The European grayling belongs to the same family, Salmonidae astrout and salmon - all have a small adipose fin.The fish is stream-lined and has a silver-grey back & flanks with black flecks and awhitish under-body.The dorsal fin is large with rows of red, blueand black spots and is bigger in the male.The mouth is quite smalland undershot, the eye teardrop shaped and the skin and fleshgive off a faint smell of the herb thyme, hence its Latin nameThymallus thymallus (L).

DistributionEuropean grayling are native to parts of England & possibly Waleshaving reached Britain before it was isolated from continentalEurope after the last ice age.They are now widely distributedthroughout Britain. All Scottish populations result from introduc-tions within the last 150 years. Grayling also reside in a few stillwa-ters, including Gouthwaite reservoir in Yorkshire & Llyn Tegid (BalaLake) in North Wales.Worldwide, many grayling populations areunder threat through overfishing, pollution and barriers preventingaccess to spawning sites.

Management of GraylingThe grayling is now recognised as an economically valuable andsought after freshwater fish. Responsibility for its management inEngland and Wales lies with the Environment Agency (EA).The EArecently focused on its future management in developing the“National Trout and Grayling Fisheries Strategy”.This aims to“enhance the social and economic benefits derived from trout andgrayling fisheries whilst ensuring the conservation of wild stocksand the aquatic environment in England & Wales” (see the EAwebsite).The EA has also published a “Review of Grayling Ecology,Status and Management” (W245), which recommends ways toraise the standard of management for this species and identifiesimportant gaps in current knowledge.

Interactions with other speciesGrayling are considered by some fishery managers to be competi-tors to brown trout. In rivers where both species live, they ofteneat similar food items.This does not mean that competition occursbetween the two species. It has long been known that where twospecies co-exist, they use food and space more efficiently thanwhen in isolation.The resulting combined production of fish isgreater. In many UK rivers food supply is plentiful and the presenceof one species probably has little effect on the other. Rather thanattempting to remove one species, it is better to make use of bothas valuable fishery resources. Grayling remain more active thantrout during the winter months and their willingness to take a flyor bait on the coldest of days can extend the fishing season andadd to the overall value of a fishery.

Grayling Removal PracticesThe grayling was previously regarded as vermin, particularly insouthern chalk streams where brown trout were the anglers quarry. Consequently they were systematically removed in largenumbers. Since the formation of an independent voluntary group,the Grayling Society in 1977, attitudes toward this species havechanged.They are now valued as a fishery resource and fishermenappreciate the fine sporting qualities that the ‘Lady of the Stream’offers particularly outside the trout season.

Removals have been made by netting, electric fishing and anglingin the misguided belief that it would improve the trout population.The different methods used to remove grayling tended to eradi-cate particular size groups. Whichever size group is removed,competition is reduced amongst the remaining grayling. In fisherieswhere grayling have been culled for many years there is no indica-tion that it has improved trout fishing. On the contrary, evidencesuggests that grayling removal may have a negative impact on the fishery.

With less competition, fish grow faster and become sexuallymature at an earlier age and smaller size. Fish maturing at twoyears will be smaller than those waiting until their third year.

Grayling that mature at a younger age are shorter lived due to in-creased spawning mortality and the average size of the fish in thefishery decreases.The resulting small average size further reinforcesa belief that grayling have a low fishery value, and adds weight tothe argument for still further removals.

Where culling has ceased, the grayling fishing has greatly improved with no impact on the quality of the trout stocks. Thelarger older grayling that have re-established now enhance theeconomic value of the fishery, especially where angling is permittedduring the winter months.

The EA recognises the economic importance of grayling stocksthrough its National Trout and Grayling Fisheries Strategy andstates “we will not undertake any large scale removal of grayling,except to re-establish a grayling fishery elsewhere”. This practise isgiven weight indirectly on SAC rivers by the protection afforded toSAC species – large-scale removals by electric fishing would onlybe allowed where it can be demonstrated not to harm SACspecies.

Fertilised eggs

• Eggs are yellowish and about 2 to 3mm in diameter.• They are deposited in pockets near the gravel surface to a

depth of 5cm.• Preferred gravel diameter ranges from 2 to 8cm.• After two to four weeks, they hatch and young alevins

emerge near the gravel surface and swim downstream.

Juveniles

• In the first months the slow marginal zones provide vital nursery areas for larvae and fry, where they feed on small animals in the water column.

• On reaching 5cm, fry can withstand greater velocities and move into faster flowing habitats.

• Larger fry occupy the area between the margins and mid channel with a sand/pebble bed where they catch drifting prey.

• As they continue to grow, the juveniles move progressively into deeper water.

Adults

• As winter approaches, adults form shoals in preparation for spawning.

• Commencement of spawning is controlled by temperature –usually between March and April.

• Sexual maturity is reached between two and four years (20-40cm in length). In many British waters, grayling rarely reach ages greater than five or six years.

• In cooler more northerly rivers in Scandinavia and Russia,grayling grow and mature more slowly with increased longevity.

• Growth slows markedly with the onset of sexual maturation and consequently a 1kg (~2.2lbs) fish is regarded as a speci-men grayling.

• Males defend territories in clean, moderately flowing water and court females approaching from downstream.

• His vibrating display and erect fins initiate spawning.

• Adults favour clean well oxygenated fast flowing water with a pebble bed in summer and deeper, slower flowing water in winter.

• They feed throughout the day and rest on the bottom at night.

• They are opportunistic feeders exploiting seasonally avail-able drifting prey, shrimps and caddis – they also consume terrestrial invertebrates.

• Prey varies with age – older fish tending to feed nearer to the river bed.

• They are unable to tolerate high water temperatures (18 to 250 C) and are very susceptible to organic pollution.

• Where their habitat requirements are fulfilled for all life stages, their home range may be only a few hundred metres.In larger rivers, migrations over many kilometres may be nec-essary to reach feeding and spawning grounds.

Grayling Lifecycle and Habitat Requirements

Comparisons of grayling populations at chalk stream sites where removal has andhas not taken place over a number of years – excludes 0+ grayling (Ibbotson)

Effect of Grayling Removal Practice on Age Structure100

80

60

40

20

0Perc

enta

ge o

f Pop

ulat

ion

(%)

1 years old > 1 years old 1 years old > 1 years old

With Removal Without Removal

Map prepared using the DMAP software written by Dr Alan Morton

pre 1972 and 1972 onwards records1972 onwards recordspre 1972 records Maitland records

Grayling distributionbased on data in the‘Database and Atlas of Freshwater Fishes’

ConservationMany rivers in England and Wales contain grayling as a result ofintroduction by man.There are a few rivers that are thought tocontain original, indigenous stocks of grayling.These include theRivers Ouse,Trent, and possibly the Severn,Wye,Thames, Ribble,Hampshire Avon and Welsh Dee. Any actions likely to affect thesegrayling populations should take their high conservation value intoaccount.

Further conservation is offered by the Grayling Society who aimto protect & preserve the grayling and its habitat as well as pro-moting angling for the species.The Society actively encourages itsangling membership to practice catch and release but they are notaverse to anglers taking the odd fish for the table - the flesh ofgrayling is palatable with some preferring the taste to that of thetrout.

Fishing RegulationsAngling regulations currently vary throughout England and Wales,but the EA will review the minimum size limits and close seasonsto ensure that all grayling have an opportunity to mature andspawn at least once. Anglers should check local byelaws and regu-lations before fishing anywhere.

Monitoring Stock and Fishery PerformanceA pilot national logbook scheme for grayling fisheries began in2001. Anglers are being asked to record simple details of theirgrayling fishing activities and catches.The data from these logbookswill be recorded over a minimum five-year period, to monitor thestatus of national and local grayling populations, fishery perfor-mance and exploitation (details are available from the EA and TheGrayling Society). Using the data collected, the EA seeks to assessthe status of wild grayling stocks and develop conservation targetsfor them.

IntroductionsThe EA’s National Trout and Grayling Fisheries Strategy states“there shall be no stocking into rivers, streams or enclosed watersoutside catchments where they are not already present, exceptpossibly to maintain an introduced population or for ‘recovering’rivers” (those improving from long-term pollution). However, pro-posals to introduce any new fish species, including grayling, mustalways be preceded by wide consultation and any introductionrequires written consent from the EA.

• Six species of grayling are found worldwide, all in the Northern Hemisphere.The European grayling is thought to have reached Britain via the “North Sea River” before Britain became isolated from continental Europe.

• Published records from Scandinavia suggest that European grayling can grow up to 9kg (~20lbs) in weight. However, it is now thought that these fish were probably white fish, since grayling are rarely seen above 1.5kg (~3lbs) in those countries.

• Grayling have been found in archaeological deposits in York dating from the 12th Century.

• In Norway, radio-tagged grayling have been recorded migrating 120km (~75miles) between their spawning and feeding grounds.

• The liver of the grayling is smaller as a percentage of body weight than in trout and many coarse fish.This means they are less able to detoxify many pollutants and are therefore good indicators of high water quality.

• At night grayling have been recorded moving from deep water into shallower, slow flowing almost still waters (dead zones).

• A 1kg (~2lbs) female grayling will lay between 4–5,000 eggs and being promiscuous, she will lay them in batches with several different males. A single female has been observed spawning nine times with seven different males over six days and on one occasion three times in five minutes.

• At the end of their first year of growth, grayling can be more than double the weight of their cousins, the trout and salmon,despite hatching later in the year.

• In the past, thousands of grayling were annually removed from rivers (particularly chalk streams) and simply buried in the fields next to the river.

• Grayling are protected in Annex V of the EC Habitats Directive.This means that their exploitation must be compatible with maintaining the grayling populations at a favourable conservationstatus. Large-scale removal of naturally occuring grayling popula-tions would rarely be consistent with this aim.

For more information about grayling, grayling fisheries and theirmanagement, contact your local Environment Agency office or localarea secretary from The Grayling Society.

Environment AgencyRio HouseWaterside DriveAztec West Telephone: 01454 624400Almondsbury Fax: 01454 624409Bristol BS32 4UD www.environment-agency.gov.uk

CEH DorsetWinfrith Technology CentreWinfrith Newburgh Telephone: 01305 213500Dorchester Fax: 01305 213600Dorset DT2 8ZD www.ceh.ac.uk

The Grayling Societyc/o 7 Oaktree WayLittle Sandhurst Telephone: 01344 775051Berkshire Fax: 01344 466604GU47 8QS www.graylingsociety.org

© Copyright - October 2002The Environment Agency/CEH/Grayling Society

No unauthorised reproduction, without written permission

An Environment Agency,Centre for Ecology and Hydrology

& Grayling Society Publication

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